The Main Argument

The Master Argument, which called'Diodorus'aporia',was developed by the Megarian philosopher Diodorus insupport of his concept of possibility. It recorded byEpictetus indicates that Diodorus had deduced acontradiction from the conjoint assertion of threepropositions. The Master Argument, which has to do withnecessity, contingency and freedom, has no the procedure ofdemonstration, but three propositions and a contradictoryconsequence.The three propositions are: A) Every true propositionabout the past is necessary, B) The impossible does notlogically follow from the possible, C) What neither ispresently true nor will be so is possible. There is aconflict between any two of them taken together and the third.Diodorus rejected the third proposition and constructedDioderean modal system. Moreover, He argued with Aristotleabout the possible. But, why the three propositions areincompatible? What is the procedure of demonstration? WhyDiodorus gave up the third proposition? Is Diodorus'solution right? In order to answer these questions, Frenchphilosopher Jules Vuillemin reconstructed the MasterArgument.Jules Vuillemin found a text in Aristotle's De Caelothat refute an incompatibility in the Platonic cosmologicalhypothesis. The text, which is a demonstration, approximates to the Master Argument. The procedure of twoand the principles used in two have large saneness.According to Jules Vuillemin, the De Caelo demonstrationbrings four principles to bear. There are: 1) the principleof conservation of the modalities, 2) the principle of thepossible realization of the possible or principle of thediachronic expansion of the modality together with theprinciple of conditional necessity, 3) the principle of theimpossibility realizing a contingent possible in the past,4) the principle of the subsistence of a possible that isnever realized. The last three of these constitute theMaster Argument as well. By these principles and two extrapremises and modern logic, Jules Vuillemin reconstructedthe De Caelo demonstration, and then the Master Argument.So ingeniously, he showed the new procedure of demonstrationof two.Moreover, by the logic of probability and the statistics,Jules Vuillemin made use of Thomas Young's two-slit set-upas an thought model, and made an unique thought-experimentto prove and illustrate Diodorus'solution in classicalmechanics and quantum mechanics respectively. Diodorus'solution is right in classical mechanics, but wrong inquantum mechanics.